#!/usr/bin/env perl

use strict;
use warnings;

my $x = "0.01 NaN 2.30 4.44";
my $r1 = join '\s+', ('([Na0-9\.\-\+]+)') x 4;
print "r1 is '$r1'\n";

my ($d, $e, $f, $g) = ($x =~ m/$r1/);
print qq($d, $e, $f, $g\n);